// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Package ethclient provides a client for the Ethereum RPC API.
package ethclient
import (
"context"
"encoding/json"
"errors"
"fmt"
"math/big"
"github.com/ava-labs/avalanchego/ids"
"github.com/ava-labs/coreth"
"github.com/ava-labs/coreth/core/types"
"github.com/ava-labs/coreth/rpc"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/rlp"
)
// Client defines typed wrappers for the Ethereum RPC API.
type Client struct {
c *rpc.Client
}
// Dial connects a client to the given URL.
func Dial(rawurl string) (*Client, error) {
return DialContext(context.Background(), rawurl)
}
func DialContext(ctx context.Context, rawurl string) (*Client, error) {
c, err := rpc.DialContext(ctx, rawurl)
if err != nil {
return nil, err
}
return NewClient(c), nil
}
// NewClient creates a client that uses the given RPC client.
func NewClient(c *rpc.Client) *Client {
return &Client{c}
}
func (ec *Client) Close() {
ec.c.Close()
}
// Blockchain Access
// ChainId retrieves the current chain ID for transaction replay protection.
func (ec *Client) ChainID(ctx context.Context) (*big.Int, error) {
var result hexutil.Big
err := ec.c.CallContext(ctx, &result, "eth_chainId")
if err != nil {
return nil, err
}
return (*big.Int)(&result), err
}
// BlockByHash returns the given full block.
//
// Note that loading full blocks requires two requests. Use HeaderByHash
// if you don't need all transactions or uncle headers.
func (ec *Client) BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error) {
return ec.getBlock(ctx, "eth_getBlockByHash", hash, true)
}
// BlockByNumber returns a block from the current canonical chain. If number is nil, the
// latest known block is returned.
//
// Note that loading full blocks requires two requests. Use HeaderByNumber
// if you don't need all transactions or uncle headers.
func (ec *Client) BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error) {
return ec.getBlock(ctx, "eth_getBlockByNumber", toBlockNumArg(number), true)
}
// BlockNumber returns the most recent block number
func (ec *Client) BlockNumber(ctx context.Context) (uint64, error) {
var result hexutil.Uint64
err := ec.c.CallContext(ctx, &result, "eth_blockNumber")
return uint64(result), err
}
type rpcBlock struct {
Hash common.Hash `json:"hash"`
Transactions []rpcTransaction `json:"transactions"`
UncleHashes []common.Hash `json:"uncles"`
Version uint32 `json:"version"`
BlockExtraData string `json:"blockExtraData"`
}
func (ec *Client) getBlock(ctx context.Context, method string, args ...interface{}) (*types.Block, error) {
var raw json.RawMessage
err := ec.c.CallContext(ctx, &raw, method, args...)
if err != nil {
return nil, err
} else if len(raw) == 0 {
return nil, coreth.NotFound
}
// Decode header and transactions.
var head *types.Header
var body rpcBlock
if err := json.Unmarshal(raw, &head); err != nil {
return nil, err
}
if err := json.Unmarshal(raw, &body); err != nil {
return nil, err
}
var blockExtraData *[]byte
if len(body.BlockExtraData) != 0 {
blockExtraDataDecoded, err := hexutil.Decode(body.BlockExtraData)
if err != nil {
return nil, fmt.Errorf("problem parsing block extra data: %w", err)
}
blockExtraData = &blockExtraDataDecoded
}
// Quick-verify transaction and uncle lists. This mostly helps with debugging the server.
if head.UncleHash == types.EmptyUncleHash && len(body.UncleHashes) > 0 {
return nil, fmt.Errorf("server returned non-empty uncle list but block header indicates no uncles")
}
if head.UncleHash != types.EmptyUncleHash && len(body.UncleHashes) == 0 {
return nil, fmt.Errorf("server returned empty uncle list but block header indicates uncles")
}
if head.TxHash == types.EmptyRootHash && len(body.Transactions) > 0 {
return nil, fmt.Errorf("server returned non-empty transaction list but block header indicates no transactions")
}
if head.TxHash != types.EmptyRootHash && len(body.Transactions) == 0 {
return nil, fmt.Errorf("server returned empty transaction list but block header indicates transactions")
}
// Load uncles because they are not included in the block response.
var uncles []*types.Header
if len(body.UncleHashes) > 0 {
uncles = make([]*types.Header, len(body.UncleHashes))
reqs := make([]rpc.BatchElem, len(body.UncleHashes))
for i := range reqs {
reqs[i] = rpc.BatchElem{
Method: "eth_getUncleByBlockHashAndIndex",
Args: []interface{}{body.Hash, hexutil